Fast fashion is a source of devastation for people and our planet alike, but when it comes to our underwear wardrobe the value of vintage is less obvious. While a consistent lifestyle might mean you can still fit into underwear you bought 10 years ago, are decades-old drawers a wise choice?

Our bodies are constantly shedding skin, hair, and bacteria as well as producing sweat. This is a natural part of being alive, but not something you want to accumulate in your clothes or underwear long-term (those bleached patches are normal, FYI). Within the microbiomes across our bodies exist harmless bacteria of which we are home to trillions. However, sometimes other bacteria such as E. coli can be a trigger for uncomfortable situations like cystitis, which is why regularly washing briefs is necessary.

“Your underwear is in close contact with your skin and more specifically your intimate areas for prolonged periods of time,” said cosmetic doctor and intimate health specialist Dr Shirin Lakhani of Elite Aesthetics in an interview with The Independent. “As a result, it takes in a lot of dead skin from those areas as well as bacteria – both the healthy, naturally-occurring bacteria that we all have, as well as more harmful bacteria that can be a result of infections such as thrush and STIs.”

Depending on the method you use to wash your underwear, it’s possible some of these could linger following a wash but unlikely. Buying new undies is a solid way to avoid this, then, but it’s probably not something you really need to be worrying about if you have access to a washing machine.

Author of The Vagina Bible and The Vajenda Dr Jennifer Gunter recently responded to a TikTok video stating that underwear should be replaced every six to nine months. As she explained to IFLScience, underwear care – for people with vulvas – really needn’t be so complicated.

“You should buy new underwear when it pleases you. There is no infectious expiration date. The idea that underwear magically become dirty after a length of time is purity culture. People who advance this falsehood typically have some kind of product to sell, either underwear or a scammy vaginal/vulvar cleanser.”

The discussion is yet another example of why you shouldn’t believe (or replicate) everything you see on TikTok (including licking a Portuguese Man o’ War). However, if you can hear the elastic in your baggy briefs it’s probably time to move on.

 THIS WEEK IN IFLSCIENCE

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